61. The blue colour of water in the sea is due to

1. 1. Refraction of the blue light by the impurities in sea water

   
   
   

   2. Scattering of blue light by water molecules

   
   
   

   3. Refraction of blue sky by sea water

   
   
   

   4. Absorption of other colours except the blue colour by water molecules

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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62. Alums help is purifycing of water through which process ?

1. 1. Making mud water soluble

   
   
   

   2. Sulphate mixed with dirt and removes it

   
   
   

   3. Coagulating the mud particles

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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63. Which one of the following is correctly matched ?

1. 1. Aerosol-smoke

   
   
   

   2. Foam-mist

   
   
   

   3. Emulsion-curd

   
   
   

   4. All of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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64. Smoke is an example of

1. 1. Gas dispersed in liquid

   
   
   

   2. Gas dispersed in solid

   
   
   

   3. Solid dispersed in gas

   
   
   

   4. Liquid dispersed in solid

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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65. The formation of colloid from suspension is

1. 1. Peptisation

   
   
   

   2. condensation

   
   
   

   3. Sedimentation

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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